Announcements 2011

10 Febrero 2011: It’s summertime in the southern hemisphere, and for the past four years this has become synonymous with a community outreach program known to Gemini staff and family as AstroDay Chile. This program, which started as a mere handful of booths and kiosks from AURA observatories in 2005, has grown to host more than 17 institutions from Chile and beyond. AstroDay Chile, continues to be a leading community outreach program for scientific and public observatories the country. However, this year (2011) a new element called Viaje al Universo Chile (Journey Through the Universe) has been adapted and added to the program. “We are always trying to improve and modify our programs in order to partner with new entities such as local universities and city halls, as well as giving the opportunity for more people to play a role in our highly visible events,” says Ma. Antonieta Garcia, who organizes the local …

26 Enero 2011: On July 19, 2009 Australian amateur astronomer Anthony Wesley spied a dark scar in the clouds of Jupiter. Wesley alerted professional astronomers and immediately both Gemini telescopes and other large telescopes around the world (and in space) trained their instruments on Jupiter’s new transient feature. Now, after more than a year of studying the unique data a team led by Glenn Orton of NASA’s Jet Propulsion Laboratory and Leigh Fletcher of Oxford University have confirmed that this collision was not like at least one similar past event. The results, published in a recent issue of the journal Icarus (see citations at the end of this feature), indicate that the colliding body was rocky and not an icy comet like the last known collision with Jupiter, the comet Shoemaker-Levy 9 in 1994. These results confirm earlier indications from Hubble Space Telescope data that the collision involved a dense rocky object rather …

25 Enero 2011: Life is busy at the Blanco 4-m telescope at Cerro Tololo Inter-American Observatory right now. This is a bird’s eye view of the dome floor during the early stages of the installation of the f/8 handler for use with the Dark Energy Camera, DECam.

20 Enero 2011: On the night of January 21-22, 2011 the Gemini South 50-watt laser began on-sky engineering testing and commissioning with its successful propagation into the sky over the summit of Cerro Pachón in Chile (see Figures a&b). The laser, an integral part of the Gemini Multi-Conjugate Adaptive Optics System (GeMS), is designed to produce five individual laser guide stars (LGS) that will help provide extremely high angular resolution over a relative wide area of the sky. Adaptive optics systems work by sampling the distortion of starlight by our atmosphere with natural and artificial (laser) guide stars and removing much of the blurring caused by our atmosphere with deformable mirrors. The technical testing and integration of the laser into the GeMS system will continue through this year as the Canopus adaptive optics system and the Gemini South Adaptive Optics Imager are also commissioned and integrated (see geminiann11002c). When complete, this will be …

10 Enero 2011: Once, the stars of any individual globular cluster were interpreted as a single population, all having formed at the same time. Over the last decade, however, evidence for multiple stellar populations has emerged. New work led by Andrea Dupree (Harvard-Smithsonian Center for Astrophysics) now shows direct evidence for helium abundance variations—a sign of multiple histories—in the bright globular cluster Omega Centauri. The team further finds that helium abundance is correlated with overall metal abundance and especially with enhancement of light elements such as aluminum and sodium, which are produced by high-temperature hydrogen burning within stars (geminiann11001a). Helium enhancement is thus likely a consequence of second-generation stars formed from enriched material processed by the earlier generation of stars. Dupree and collaborators, Jay Strader (Harvard-Smithsonian Center for Astrophysics) and Graeme Smith (University of California Observatories/Lick Observatory), used the Phoenix high-resolution spectrograph on Gemini South to measure the near-infrared helium line at a …